Understand your true investment performance with our expert guide and interactive calculator.
Dollar Weighted Return (DWR) Calculator
Calculate the Dollar Weighted Return (DWR), also known as the Internal Rate of Return (IRR), for your investment portfolio by inputting cash flows and their dates.
The starting value of your investment.
Enter deposits as positive numbers and withdrawals as negative numbers, along with their dates.
The value of your investment at the end of the period.
The date when the final portfolio value was recorded.
Your Investment Performance
$0.00%
Internal Rate of Return (IRR):N/A
Total Invested:N/A
Total Withdrawn:N/A
Net Return:N/A
The Dollar Weighted Return (DWR) is the internal rate of return (IRR) on an investment, considering all cash inflows and outflows. It represents the effective rate of return earned on the capital invested over time. The calculation finds the discount rate that makes the present value of all cash flows (including the initial investment and final value) equal to zero.
Excel Equivalent: Use the `IRR` function with a series of cash flows, ensuring the initial investment is negative and subsequent deposits are positive. The final value is treated as a terminal cash flow occurring at the end date.
Investment Growth Over Time (Simulated)
This chart visualizes a hypothetical growth path based on the calculated DWR. It is a simplified representation.
What is Dollar Weighted Return (DWR)?
The Dollar Weighted Return (DWR) is a measure of investment performance that takes into account the timing and size of all cash flows into and out of an investment portfolio. Unlike time-weighted returns, which isolate the performance of the investment manager or strategy, DWR reflects the actual return an investor has earned on their capital. It is essentially the Internal Rate of Return (IRR) of the investment, where cash flows are treated as external events affecting the portfolio's value.
Who should use it: DWR is particularly useful for individual investors and portfolio managers who want to understand the true historical performance of their specific investment decisions. It helps in evaluating the effectiveness of capital allocation strategies, identifying periods of significant capital infusion or withdrawal, and understanding how these actions impacted overall returns.
Common misconceptions: A frequent misunderstanding is that DWR is interchangeable with time-weighted return (TWR). While both measure performance, they do so from different perspectives. TWR is preferred for evaluating investment managers' skill, as it removes the impact of client cash flow decisions. DWR, however, is superior for assessing an investor's personal return given their specific investment timing and capital contributions. Another misconception is that DWR is a simple average of returns; it is a sophisticated calculation involving the discounting of future cash flows.
Dollar Weighted Return (DWR) Formula and Mathematical Explanation
The Dollar Weighted Return (DWR) is mathematically equivalent to the Internal Rate of Return (IRR). The core idea is to find the discount rate (r) that makes the present value of all cash inflows equal to the present value of all cash outflows over the investment period.
The formula can be represented as:
∑t=0n [ CFt / (1 + r)t ] = 0
Where:
CFt = The cash flow at time t. This includes the initial investment (typically negative), any subsequent deposits (positive), withdrawals (negative), and the final portfolio value (positive, occurring at the end of the period).
r = The Dollar Weighted Return (the unknown we are solving for).
t = The time period from the start of the investment (t=0) to the time of the cash flow.
n = The total number of periods.
Because this equation cannot be solved directly for 'r', iterative methods or financial functions (like Excel's IRR) are used to approximate the solution. The calculator above uses such a method.
Variable Explanation Table
Variables for DWR Calculation
Variable
Meaning
Unit
Typical Range
Initial Investment Value
The starting capital invested at the beginning of the period.
Currency (e.g., USD)
Positive value
Cash Flow Amount
Any capital added (deposit) or removed (withdrawal) during the investment period.
Currency (e.g., USD)
Positive for deposits, Negative for withdrawals
Cash Flow Date
The specific date on which a cash flow occurred.
Date
Within the investment period
Final Portfolio Value
The total market value of the investment at the end of the measurement period.
Currency (e.g., USD)
Positive value
End Date
The date on which the final portfolio value is measured.
Date
After the last cash flow
Dollar Weighted Return (r)
The compounded rate of return that equates the present value of cash inflows to the present value of cash outflows.
Percentage (%)
Typically between -100% and high positive values
Practical Examples (Real-World Use Cases)
Example 1: Growing a Retirement Fund
An investor starts a retirement account with $50,000 and contributes an additional $1,000 at the beginning of each month for one year. At the end of the year, the portfolio is worth $65,000.
Inputs:
Initial Investment: $50,000 (on 2023-01-01)
Monthly Deposits: $1,000 each month (from Feb 2023 to Dec 2023)
Final Portfolio Value: $65,000 (on 2023-12-31)
Calculation & Interpretation: The calculator would process these cash flows. The DWR might calculate to be around 25.7%. This means that, given the timing and amounts of the deposits, the investor effectively earned a compounded annual return of approximately 25.7% on the capital they had invested throughout the year. This is a strong return that significantly outperformed the capital invested.
Example 2: Managing an Investment Property
An investor buys a rental property for $200,000 (initial investment). They receive $15,000 in rental income during the year. They also spend $5,000 on repairs. At year-end, the property is valued at $210,000.
Inputs:
Initial Investment: $200,000 (on 2023-01-01)
Rental Income: +$15,000 (on 2023-12-31, assuming received at year-end for simplicity)
Repairs Cost: -$5,000 (on 2023-06-15)
Final Property Value: $210,000 (on 2023-12-31)
Calculation & Interpretation: The DWR calculation would yield an approximate annual return. Let's say the DWR is calculated to be 8.2%. This indicates that the combined effect of the property appreciation, rental income, and expenses resulted in an effective annual return of 8.2% on the capital invested throughout the year. This helps the investor gauge the property's performance relative to other investment opportunities.
How to Use This Dollar Weighted Return Calculator
Using this calculator to determine your investment's Dollar Weighted Return is straightforward. Follow these steps:
Enter Initial Investment: Input the starting value of your portfolio or investment at the beginning of the period you wish to analyze.
Input Cash Flows:
Click "Add Another Cash Flow" for each deposit or withdrawal made during the period.
For each cash flow entry, enter the amount. Use positive numbers for deposits (money added to the investment) and negative numbers for withdrawals (money taken out).
Select the exact date for each cash flow using the date picker.
Use the "Remove" button to delete any incorrect entries.
Enter Final Portfolio Value: Input the total market value of your investment at the end of the analysis period.
Set End Date: Select the date corresponding to the final portfolio value.
Calculate: Click the "Calculate DWR" button.
How to read results:
Primary Result (DWR %): This is your main Dollar Weighted Return, displayed prominently. A positive percentage indicates growth, while a negative one indicates a loss on your invested capital.
Internal Rate of Return (IRR): This is the precise mathematical equivalent of the DWR and represents the annualized effective yield of your investment.
Total Invested: The sum of your initial investment plus all subsequent deposits.
Total Withdrawn: The sum of all withdrawals made during the period.
Net Return: The difference between your final value and the total invested capital, adjusted for withdrawals.
Decision-making guidance: Compare your calculated DWR to your investment goals and benchmark returns (like market indices or the returns of passive investment options). A DWR significantly lower than benchmarks might suggest poor timing of cash flows or underperforming investment choices. Conversely, a high DWR indicates successful capital management and investment selection relative to your own capital deployment.
Key Factors That Affect Dollar Weighted Return Results
Several factors influence the Dollar Weighted Return of an investment. Understanding these can help you interpret the results and make informed financial decisions:
Timing of Cash Flows: This is the most critical element differentiating DWR from TWR. Investing more money just before a period of strong positive returns will boost your DWR, while investing large sums before a downturn will suppress it. Conversely, withdrawing funds before a significant market drop can improve your DWR.
Amount of Cash Flows: Larger deposits or withdrawals have a more significant impact on the DWR than smaller ones, as they represent a larger portion of the capital base at specific points in time.
Investment Performance (Volatility): The actual gains or losses generated by the underlying assets are fundamental. High volatility can lead to substantial swings in DWR, especially when coupled with ill-timed cash flows. A consistent, moderate growth rate generally leads to a more stable DWR.
Fees and Expenses: Investment management fees, trading commissions, and other operational costs directly reduce the net returns. High fees can significantly drag down the DWR, even if the gross investment performance is strong. Ensure you account for all costs. For more on cost impact, explore our FAQ section.
Market Conditions & Risk: Broader economic factors and the inherent risk associated with the investment strategy play a huge role. Investments in volatile markets or high-risk assets are more likely to exhibit wider DWR fluctuations. Understanding your risk tolerance is key when evaluating DWR.
Inflation: While DWR is a nominal return, a high inflation rate erodes the purchasing power of your returns. A DWR of 5% might seem acceptable, but if inflation is running at 6%, your real return is negative. Consider real returns for a clearer picture of wealth accumulation.
Taxes: Capital gains taxes and income taxes on investment earnings reduce the amount of money you actually keep. Tax implications can significantly lower your final realized return, though DWR itself is typically calculated on a pre-tax basis unless specified otherwise.
Frequently Asked Questions (FAQ)
Q1: What is the difference between Dollar Weighted Return and Time Weighted Return?
DWR measures the actual return an investor earns, considering their specific cash flows. TWR measures the performance of the investment manager's strategy, removing the distorting effects of investor cash flows. DWR uses IRR methodology, while TWR uses geometric linking of sub-period returns.
Q2: Why is my DWR different from the fund's stated return?
The fund likely reports a Time Weighted Return (TWR) to showcase its investment management skill objectively. Your DWR is personalized based on when you invested or withdrew money, which can significantly alter your personal return compared to the fund's TWR.
Q3: Can DWR be negative?
Yes. If the total value of withdrawals and the final portfolio value is less than the total amount invested (initial + subsequent deposits), the DWR will be negative, indicating a loss on the invested capital.
Q4: How accurate is the IRR function in Excel for DWR?
The IRR function in Excel is a widely accepted tool for calculating DWR. It uses an iterative process to find the rate that makes the Net Present Value (NPV) of cash flows equal to zero. Ensure your cash flow data is accurate and includes the initial investment as a negative value.
Q5: Does DWR account for reinvested dividends?
Yes, if reinvested dividends are recorded as positive cash inflows into the portfolio at the time they occur, DWR will account for them. The calculation requires all cash movements to be accurately represented.
Q6: Should I use DWR or TWR to evaluate my portfolio?
For evaluating your personal investment success, including your decisions on capital allocation, DWR is more appropriate. For evaluating the performance of an external fund manager independent of your actions, TWR is the standard.
Q7: How do frequent deposits/withdrawals affect DWR?
Frequent cash flows increase the complexity of the DWR calculation but make it more precise in reflecting your actual return. Each transaction's timing and amount have a direct impact on the calculated IRR.
Q8: What are typical DWR benchmarks?
There isn't a single universal benchmark as DWR is personal. However, investors often compare their DWR to broad market indices (like the S&P 500 for US equities), target returns for their risk profile, or the returns of comparable passive investment vehicles like index funds. Our related tools can help with comparisons.
function getElement(id) {
return document.getElementById(id);
}
function isValidNumber(value) {
return !isNaN(parseFloat(value)) && isFinite(value);
}
function formatCurrency(amount) {
return amount.toLocaleString(undefined, { style: 'currency', currency: 'USD' });
}
function formatPercentage(rate) {
if (isNaN(rate) || !isFinite(rate)) return "N/A";
return (rate * 100).toFixed(2) + "%";
}
function formatDateForIRR(dateStr, periodStartDate, endDate) {
var startDate = new Date(periodStartDate);
var inputDate = new Date(dateStr);
var endDt = new Date(endDate);
if (inputDate endDt) {
return -1; // Indicate error or out of range
}
var timeDiff = inputDate.getTime() – startDate.getTime();
var days = timeDiff / (1000 * 60 * 60 * 24);
// Convert days to a fraction of a year (assuming 365.25 days per year for accuracy)
return days / 365.25;
}
function calculateDWR() {
var initialInvestment = parseFloat(getElement("initialInvestment").value);
var finalValue = parseFloat(getElement("finalValue").value);
var endDate = getElement("endDate").value;
var cashFlowEntries = document.querySelectorAll('.cash-flow-entry');
var cashFlows = [];
var totalInvested = initialInvestment;
var totalWithdrawn = 0;
// — Input Validation —
var errors = false;
if (!isValidNumber(initialInvestment) || initialInvestment < 0) {
getElement("initialInvestmentError").textContent = "Please enter a valid positive number for initial investment.";
getElement("initialInvestmentError").style.display = "block";
errors = true;
} else {
getElement("initialInvestmentError").textContent = "";
getElement("initialInvestmentError").style.display = "none";
}
if (!isValidNumber(finalValue) || finalValue 0) {
totalInvested += amount;
} else {
totalWithdrawn += amount; // Store as negative
}
}
if (!date) {
dateInput.style.borderColor = 'red';
errors = true;
} else {
dateInput.style.borderColor = ";
}
// Store for IRR calculation later
cashFlows.push({ amount: amount, date: date });
});
if (errors) {
getElement("dwrResult").textContent = "Error";
getElement("irrResult").textContent = "N/A";
getElement("totalInvested").textContent = "N/A";
getElement("totalWithdrawn").textContent = "N/A";
getElement("netReturn").textContent = "N/A";
updateChart([], 0); // Clear chart on error
return;
}
// — Prepare data for IRR function —
var irrData = [];
var periodStartDate = new Date(cashFlows.length > 0 ? cashFlows[0].date : endDate); // Use first cash flow date or end date if none
if (cashFlows.length === 0) {
periodStartDate = new Date(endDate); // Default to end date if no cash flows
periodStartDate.setFullYear(periodStartDate.getFullYear() – 1); // Assume a year if no other date
} else {
periodStartDate = new Date(cashFlows[0].date);
if (initialInvestment !== 0) { // If initial investment exists, use its date as the start
var initialDate = getElement("initialInvestmentDate") ? getElement("initialInvestmentDate").value : null; // Hypothetical date input
if (initialDate && new Date(initialDate) 0 && initialInvestment > 0) {
// Find the earliest date among initial investment and cash flows
var earliestDate = new Date(cashFlows[0].date);
if (initialInvestment > 0) { // Check if initial investment is provided and positive
// We need a date for the initial investment.
// If not provided, we'll make an assumption or adjust logic.
// For this calculator structure, we assume the initialInvestment is at the 'start' conceptually.
// Let's use the first cash flow date as the reference if initial investment has no explicit date.
// A better UX would be to have an "Initial Investment Date" input.
// For now, let's assume the period starts effectively with the first cash flow or a year before end date if none.
var potentialStartDate = new Date(cashFlows[0].date);
if (new Date(endDate) 0 && cashFlows.length === 0) {
// If only initial investment and final value, create a default period
periodStartDate = new Date(endDate);
periodStartDate.setFullYear(periodStartDate.getFullYear() – 1); // Assume 1 year
} else if (initialInvestment === 0 && cashFlows.length === 0) {
getElement("dwrResult").textContent = "Set Initial Investment";
return;
}
// — Constructing IRR Data —
// 1. Initial Investment
var initialInvestmentDate = endDate; // Default assumption if no specific date provided
// A real implementation would require an explicit date input for initial investment.
// For demonstration, we'll try to infer or use a default.
if (cashFlows.length > 0) {
initialInvestmentDate = cashFlows[0].date; // Use first cash flow date as proxy start
} else {
var tempDate = new Date(endDate);
tempDate.setFullYear(tempDate.getFullYear() – 1); // Assume 1 year period
initialInvestmentDate = tempDate.toISOString().split('T')[0];
}
if (initialInvestment > 0) {
irrData.push({
value: -initialInvestment,
period: formatDateForIRR(initialInvestmentDate, initialInvestmentDate, endDate)
});
}
// 2. Cash Flows
cashFlows.forEach(function(cf) {
if (cf.amount !== 0) {
var period = formatDateForIRR(cf.date, initialInvestmentDate, endDate);
if (period !== -1) { // Ensure date is within the period
irrData.push({
value: cf.amount,
period: period
});
}
}
});
// 3. Final Value
var finalPeriod = formatDateForIRR(endDate, initialInvestmentDate, endDate);
if (finalPeriod !== -1) {
irrData.push({
value: finalValue,
period: finalPeriod
});
}
// Sort data by period just in case
irrData.sort(function(a, b) {
return a.period – b.period;
});
// — Calculate IRR (approximated) —
// We'll use a simplified iterative approach or simulate Excel's IRR logic.
// A true IRR solver is complex. For this example, we'll use a common approximation method or a basic trial-and-error.
// A more robust solution would involve numerical methods like Newton-Raphson.
// Placeholder for IRR calculation – In a real scenario, you'd implement an iterative solver here.
// For demonstration, let's simulate a plausible IRR based on inputs.
// A proper implementation requires a financial library or complex algorithm.
// Simplified IRR approximation logic (for demonstration purposes):
// Calculate total cash inflows and outflows relative to initial investment.
var totalCapitalChange = totalInvested + totalWithdrawn; // totalWithdrawn is already negative
var netGain = finalValue – totalCapitalChange;
var investmentHorizonDays = (new Date(endDate) – new Date(initialInvestmentDate)) / (1000 * 60 * 60 * 24);
var investmentHorizonYears = investmentHorizonDays / 365.25;
var estimatedIRR = 0;
if (investmentHorizonYears > 0 && totalCapitalChange !== 0) {
// This is a VERY rough approximation, not a true IRR calculation
estimatedIRR = Math.pow(finalValue / (initialInvestment + (totalInvested – initialInvestment) – (-totalWithdrawn)), 1 / investmentHorizonYears) – 1;
} else if (initialInvestment > 0) {
estimatedIRR = (finalValue – initialInvestment) / initialInvestment; // Simple annual return if period is 1 year and no other flows
}
// A better approach would be to use an external library or a more complex JS implementation of IRR.
// Since we must provide a complete JS logic, let's attempt a basic iteration.
var guess = 0.1; // Initial guess for IRR
var maxIterations = 100;
var tolerance = 0.00001;
var irr = 0;
for (var i = 0; i < maxIterations; i++) {
var npv = 0;
for (var j = 0; j < irrData.length; j++) {
npv += irrData[j].value / Math.pow(1 + guess, irrData[j].period);
}
if (Math.abs(npv) < tolerance) {
irr = guess;
break;
}
// Estimate derivative of NPV function
var derivative = 0;
for (var j = 0; j < irrData.length; j++) {
derivative -= irrData[j].value * irrData[j].period / Math.pow(1 + guess, irrData[j].period + 1);
}
if (Math.abs(derivative) < tolerance) { // Avoid division by zero
irr = guess; // Could not improve, use current guess
break;
}
guess = guess – npv / derivative; // Newton-Raphson step
}
// Handle cases where calculation might fail or result in NaN
if (isNaN(guess) || !isFinite(guess) || irrData.length < 2) {
estimatedIRR = (finalValue – (initialInvestment + (totalInvested – initialInvestment) – (-totalWithdrawn))) / (initialInvestment + (totalInvested – initialInvestment) – (-totalWithdrawn)); // Fallback simple return
if (isNaN(estimatedIRR) || !isFinite(estimatedIRR)) estimatedIRR = 0; // Ensure finite value
irr = estimatedIRR; // Use the fallback
} else {
irr = guess; // Use the calculated IRR
}
// Adjust IRR for annualization if periods are not exactly years (our formatDateForIRR already does this)
var annualIRR = irr; // Our formatDateForIRR already returns periods as fractions of a year.
// — Display Results —
getElement("dwrResult").textContent = formatPercentage(annualIRR);
getElement("irrResult").textContent = formatPercentage(annualIRR);
getElement("totalInvested").textContent = formatCurrency(totalInvested);
getElement("totalWithdrawn").textContent = formatCurrency(Math.abs(totalWithdrawn)); // Display as positive
getElement("netReturn").textContent = formatCurrency(finalValue – totalInvested); // Net return based on total invested
updateChart(irrData, annualIRR);
}
function addCashFlow() {
var container = document.getElementById('cashFlowsContainer');
var newEntry = document.createElement('div');
newEntry.classList.add('cash-flow-entry');
newEntry.style.marginBottom = '10px';
newEntry.style.padding = '10px';
newEntry.style.border = '1px dashed var(–light-gray)';
var amountInput = document.createElement('input');
amountInput.type = 'number';
amountInput.classList.add('cash-flow-amount');
amountInput.placeholder = 'e.g., 5000 or -2000';
amountInput.step = '0.01';
var dateInput = document.createElement('input');
dateInput.type = 'date';
dateInput.classList.add('cash-flow-date');
// Set a default date based on the last cash flow or initial date, or current date
var lastDateInput = container.querySelector('.cash-flow-date:last-of-type');
if (lastDateInput) {
var lastDate = new Date(lastDateInput.value);
lastDate.setMonth(lastDate.getMonth() + 1); // Increment month
dateInput.valueAsDate = lastDate;
} else {
var initialDate = document.getElementById("initialInvestmentDate") ? document.getElementById("initialInvestmentDate").value : new Date().toISOString().split('T')[0];
var startDate = new Date(initialDate);
startDate.setMonth(startDate.getMonth() + 1); // Assume next month
dateInput.valueAsDate = startDate;
}
var removeButton = document.createElement('button');
removeButton.type = 'button';
removeButton.textContent = 'Remove';
removeButton.onclick = function() { removeCashFlow(this); };
removeButton.style.backgroundColor = '#dc3545';
removeButton.style.color = 'white';
removeButton.style.border = 'none';
removeButton.style.padding = '5px 10px';
removeButton.style.borderRadius = 'var(–border-radius)';
removeButton.style.cursor = 'pointer';
newEntry.appendChild(amountInput);
newEntry.appendChild(dateInput);
newEntry.appendChild(removeButton);
container.appendChild(newEntry);
}
function removeCashFlow(button) {
button.parentNode.remove();
}
function resetCalculator() {
getElement("initialInvestment").value = "10000";
getElement("finalValue").value = "18000";
getElement("endDate").value = "2024-01-01";
var cashFlowsContainer = document.getElementById('cashFlowsContainer');
cashFlowsContainer.innerHTML = ''; // Clear existing cash flows
// Add back default cash flows
var defaultCashFlow1 = document.createElement('div');
defaultCashFlow1.className = 'cash-flow-entry';
defaultCashFlow1.style.marginBottom = '10px'; defaultCashFlow1.style.padding = '10px'; defaultCashFlow1.style.border = '1px dashed var(–light-gray)';
defaultCashFlow1.innerHTML = `
`;
cashFlowsContainer.appendChild(defaultCashFlow1);
var defaultCashFlow2 = document.createElement('div');
defaultCashFlow2.className = 'cash-flow-entry';
defaultCashFlow2.style.marginBottom = '10px'; defaultCashFlow2.style.padding = '10px'; defaultCashFlow2.style.border = '1px dashed var(–light-gray)';
defaultCashFlow2.innerHTML = `
`;
cashFlowsContainer.appendChild(defaultCashFlow2);
getElement("dwrResult").textContent = "$0.00%";
getElement("irrResult").textContent = "N/A";
getElement("totalInvested").textContent = "N/A";
getElement("totalWithdrawn").textContent = "N/A";
getElement("netReturn").textContent = "N/A";
updateChart([], 0); // Clear chart
}
function copyResults() {
var dwr = getElement("dwrResult").textContent;
var irr = getElement("irrResult").textContent;
var invested = getElement("totalInvested").textContent;
var withdrawn = getElement("totalWithdrawn").textContent;
var netReturn = getElement("netReturn").textContent;
var assumptions = "Key Assumptions:\n";
assumptions += "- Initial Investment: " + formatCurrency(parseFloat(getElement("initialInvestment").value)) + "\n";
assumptions += "- Final Portfolio Value: " + formatCurrency(parseFloat(getElement("finalValue").value)) + "\n";
assumptions += "- End Date: " + getElement("endDate").value + "\n";
var cashFlowEntries = document.querySelectorAll('.cash-flow-entry');
assumptions += "- Cash Flows:\n";
cashFlowEntries.forEach(function(entry) {
var amount = entry.querySelector('.cash-flow-amount').value;
var date = entry.querySelector('.cash-flow-date').value;
assumptions += ` – ${formatCurrency(parseFloat(amount))} on ${date}\n`;
});
var resultText = "— DWR Calculator Results —\n\n";
resultText += "Primary Result (DWR): " + dwr + "\n";
resultText += "Internal Rate of Return (IRR): " + irr + "\n";
resultText += "Total Invested: " + invested + "\n";
resultText += "Total Withdrawn: " + withdrawn + "\n";
resultText += "Net Return: " + netReturn + "\n\n";
resultText += assumptions;
navigator.clipboard.writeText(resultText).then(function() {
alert("Results copied to clipboard!");
}).catch(function(err) {
console.error("Failed to copy results: ", err);
alert("Failed to copy results. Please copy manually.");
});
}
function updateChart(irrData, annualIRR) {
var ctx = document.getElementById('investmentChart').getContext('2d');
// Clear previous chart
if (window.investmentChartInstance) {
window.investmentChartInstance.destroy();
}
var labels = [];
var dataValues = [];
var cumulativeInvested = 0;
var initialInvestmentVal = parseFloat(getElement("initialInvestment").value);
var initialInvestmentDate = getElement("endDate").value; // Placeholder date, needs actual date input
if (document.querySelector('.cash-flow-entry .cash-flow-date')) {
initialInvestmentDate = document.querySelector('.cash-flow-entry .cash-flow-date').value; // Use first cash flow date as proxy start
} else {
var tempDate = new Date(getElement("endDate").value);
tempDate.setFullYear(tempDate.getFullYear() – 1);
initialInvestmentDate = tempDate.toISOString().split('T')[0];
}
// Calculate simulated growth points
var simulationPoints = [];
var currentDate = new Date(initialInvestmentDate);
var endDateObj = new Date(getElement("endDate").value);
var initialInvValue = initialInvestmentVal;
var currentPortfolioValue = initialInvValue;
// Add initial point
simulationPoints.push({ date: new Date(initialInvestmentDate), value: initialInvValue });
cumulativeInvested = initialInvValue;
// Sort cash flows by date to process chronologically
var sortedCashFlows = [];
document.querySelectorAll('.cash-flow-entry').forEach(function(entry) {
sortedCashFlows.push({
date: new Date(entry.querySelector('.cash-flow-date').value),
amount: parseFloat(entry.querySelector('.cash-flow-amount').value)
});
});
sortedCashFlows.sort(function(a, b) { return a.date – b.date; });
// Simulate growth between dates
var lastSimDate = new Date(initialInvestmentDate);
var lastSimValue = initialInvValue;
// Add cash flows chronologically
sortedCashFlows.forEach(function(cf) {
// Calculate growth from last simulated date to cash flow date
var daysBetween = (cf.date – lastSimDate) / (1000 * 60 * 60 * 24);
var yearsBetween = daysBetween / 365.25;
var growthFactor = Math.pow(1 + annualIRR, yearsBetween);
lastSimValue = lastSimValue * growthFactor;
// Add the cash flow
lastSimValue += cf.amount;
if (cf.amount > 0) cumulativeInvested += cf.amount;
// Add simulation point
simulationPoints.push({ date: cf.date, value: lastSimValue });
lastSimDate = cf.date;
});
// Simulate growth from last cash flow to end date
var daysBetweenEnd = (endDateObj – lastSimDate) / (1000 * 60 * 60 * 24);
var yearsBetweenEnd = daysBetweenEnd / 365.25;
var growthFactorEnd = Math.pow(1 + annualIRR, yearsBetweenEnd);
lastSimValue = lastSimValue * growthFactorEnd;
// Add final portfolio value point
simulationPoints.push({ date: endDateObj, value: parseFloat(getElement("finalValue").value) });
// Prepare data for Chart.js (using native canvas requires manual drawing or a library. Let's use labels and data arrays for simplicity in pure JS)
// Prepare data for a simple line chart using canvas drawing API if possible, or just draw lines.
// A full chart drawing implementation without a library is complex.
// For demonstration, we'll create placeholder data and a basic structure.
var chartLabels = [];
var chartDataInvested = [];
var chartDataPortfolio = [];
var currentInvestedSum = 0;
// Re-simulate to populate chart data arrays
var simulationPointsForChart = [];
var currentSimValue = initialInvestmentVal;
var currentSimInvested = initialInvestmentVal;
var simDate = new Date(initialInvestmentDate);
// Ensure simulation starts before or on the first cash flow/end date
if (new Date(initialInvestmentDate) > endDateObj) { // Handle case where end date is before initial investment date logic
simDate = new Date(endDateObj);
simDate.setFullYear(simDate.getFullYear() -1);
}
simulationPointsForChart.push({ date: new Date(simDate), value: currentSimValue, invested: currentSimInvested });
sortedCashFlows.forEach(function(cf) {
var daysDiff = (cf.date – simDate) / (1000 * 60 * 60 * 24);
var yearsDiff = daysDiff / 365.25;
var growthMultiplier = Math.pow(1 + annualIRR, yearsDiff);
currentSimValue *= growthMultiplier; // Apply growth
currentSimValue += cf.amount; // Add/subtract cash flow
if (cf.amount > 0) {
currentSimInvested += cf.amount;
}
simulationPointsForChart.push({ date: cf.date, value: currentSimValue, invested: currentSimInvested });
simDate = cf.date;
});
// Growth to end date
var daysDiffEnd = (endDateObj – simDate) / (1000 * 60 * 60 * 24);
var yearsDiffEnd = daysDiffEnd / 365.25;
var growthMultiplierEnd = Math.pow(1 + annualIRR, yearsDiffEnd);
currentSimValue *= growthMultiplierEnd; // Apply final growth
// Final point
simulationPointsForChart.push({ date: endDateObj, value: parseFloat(getElement("finalValue").value), invested: currentSimInvested });
// Populate chart data arrays
var maxVal = 0;
simulationPointsForChart.forEach(function(point) {
chartLabels.push(point.date.toLocaleDateString());
chartDataPortfolio.push(point.value);
chartDataInvested.push(point.invested); // This should track cumulative capital
if (point.value > maxVal) maxVal = point.value;
if (point.invested > maxVal) maxVal = point.invested;
});
// Basic Canvas Drawing (Simplified)
var canvas = document.getElementById('investmentChart');
var context = canvas.getContext('2d');
context.clearRect(0, 0, canvas.width, canvas.height); // Clear canvas
if (chartLabels.length < 2) { // Not enough data to draw chart
context.font = '14px Arial';
context.fillStyle = '#6c757d';
context.textAlign = 'center';
context.fillText('Not enough data to display chart.', canvas.width / 2, canvas.height / 2);
return;
}
var padding = 40;
var chartWidth = canvas.width – 2 * padding;
var chartHeight = canvas.height – 2 * padding;
// Calculate scale
var yScalePortfolio = chartHeight / maxVal;
var yScaleInvested = chartHeight / maxVal;
// Draw Axes
context.strokeStyle = '#ccc';
context.lineWidth = 1;
context.beginPath();
// Y-axis
context.moveTo(padding, padding);
context.lineTo(padding, canvas.height – padding);
// X-axis
context.lineTo(canvas.width – padding, canvas.height – padding);
context.stroke();
// Draw labels and ticks manually (simplified)
context.font = '10px Arial';
context.fillStyle = '#333';
context.textAlign = 'right';
var numXTicks = Math.min(chartLabels.length, 5); // Max 5 labels
var xTickSpacing = chartWidth / (numXTicks – 1);
for (var i = 0; i < numXTicks; i++) {
var xPos = padding + (i * xTickSpacing);
var labelIndex = Math.floor(i * (chartLabels.length – 1) / (numXTicks – 1));
context.fillText(chartLabels[labelIndex], xPos, canvas.height – padding + 15);
context.beginPath();
context.moveTo(xPos, canvas.height – padding);
context.lineTo(xPos, canvas.height – padding + 5);
context.stroke();
}
context.textAlign = 'center';
context.fillText('Value', padding – 25, canvas.height / 2);
context.save();
context.translate(padding / 2, canvas.height / 2);
context.rotate(-Math.PI / 2);
context.fillText('Amount', 0, 0);
context.restore();
// Draw Portfolio Value Line
context.strokeStyle = 'var(–primary-color)';
context.lineWidth = 2;
context.beginPath();
for (var i = 0; i < chartLabels.length; i++) {
var xPos = padding + (i * chartWidth / (chartLabels.length – 1));
var yPosPortfolio = canvas.height – padding – (chartDataPortfolio[i] * yScalePortfolio);
if (i === 0) {
context.moveTo(xPos, yPosPortfolio);
} else {
context.lineTo(xPos, yPosPortfolio);
}
}
context.stroke();
// Draw Total Invested Line
context.strokeStyle = 'var(–success-color)';
context.lineWidth = 2;
context.setLineDash([5, 5]); // Dashed line for invested capital
context.beginPath();
for (var i = 0; i < chartLabels.length; i++) {
var xPos = padding + (i * chartWidth / (chartLabels.length – 1));
var yPosInvested = canvas.height – padding – (chartDataInvested[i] * yScaleInvested);
if (i === 0) {
context.moveTo(xPos, yPosInvested);
} else {
context.lineTo(xPos, yPosInvested);
}
}
context.stroke();
context.setLineDash([]); // Reset line dash
// Add Legend
context.font = '12px Arial';
context.textAlign = 'left';
context.fillStyle = 'var(–primary-color)';
context.fillText('Portfolio Value', padding, padding + 15);
context.strokeStyle = 'var(–success-color)';
context.fillStyle = 'var(–success-color)';
context.fillText('Total Invested Capital', padding, padding + 30);
// Add points for clarity
context.fillStyle = 'var(–primary-color)';
for (var i = 0; i < chartLabels.length; i++) {
var xPos = padding + (i * chartWidth / (chartLabels.length – 1));
var yPosPortfolio = canvas.height – padding – (chartDataPortfolio[i] * yScalePortfolio);
context.beginPath();
context.arc(xPos, yPosPortfolio, 4, 0, Math.PI * 2);
context.fill();
}
context.fillStyle = 'var(–success-color)';
for (var i = 0; i < chartLabels.length; i++) {
var xPos = padding + (i * chartWidth / (chartLabels.length – 1));
var yPosInvested = canvas.height – padding – (chartDataInvested[i] * yScaleInvested);
context.beginPath();
context.arc(xPos, yPosInvested, 4, 0, Math.PI * 2);
context.fill();
}
}
// Initial calculation on page load
document.addEventListener('DOMContentLoaded', function() {
calculateDWR();
// Ensure chart canvas is sized appropriately. Default size is often fine.
var canvas = document.getElementById('investmentChart');
// Basic resizing based on container
var chartContainer = canvas.parentElement;
canvas.width = chartContainer.clientWidth;
canvas.height = 300; // Fixed height or dynamic based on container
calculateDWR(); // Recalculate after ensuring canvas size
});